Conventionally, there are various types of roll paper holders for rotatably holding a roll paper (that is, a roll of paper, as may also be referred to as rolled paper). As a roll paper holder having a member for pressing a side end of the roll paper, there is a roll paper holder which elastically presses the side end of the roll paper, and a roll paper holder which matches an interval between a pair of side walls with a width of the roll paper.
In a conventional printer that performs printing on the roll paper obtained by winding the paper, a paper guide that guides the paper to determine the position in the width direction of the paper is provided between the roll paper holder and a printing section.